Envenoming following scorpion sting is a common emergency in many parts of the world. Our aim was to ameliorate the current 100‐kDa horse plasma antivenom serum (PAS)‐derived Fab′ ₂ to more quickly reach the highly diffusible scorpion toxins (7 kDa). We immunized dromedaries with toxins from Androctonus australis hector (Aah) scorpions and cloned the single‐domain antibody fragments or nanobodies (15 kDa) from their B cells. Nanobodies against AahI′ toxin (with AahII the most toxic compound of the venom) were retrieved from the libraries, and their AahI′ ‐toxin neutralization was monitored in mice. Remarkably, the NbAahI′ F12 fully protected mice against 100 LD ₅₀ of AahI′ administered intracerebroventricularly. Moreover, where PAS failed completely to neutralize 2 LD ₅₀ of crude venom injected subcutaneously, the designed bispecific NbF12‐10 against AahI′/AahII toxins succeeded in neutralizing 5 LD ₅₀ . Finally, in a challenge assay in which mice were subcutaneously injected with a lethal dose of scorpion venom, the subsequent intravenous injection of 85 μg of NbF12‐10 protected all mice, even if the whole procedure was repeated 3 times. Furthermore, the NbF12‐10 remained fully protective when mice with severe signs of envenoming were treated a few minutes before the untreated mice died.—Hmila, I., Saerens, D., Ben Abderrazek, R., Vincke, C., Abidi, N., Benlasfar, Z., Govaert, J., El Ayeb, M., Bouhaouala‐Zahar, B., Muyldermans, S. A bispecific nanobody to provide full protection against lethal scorpion envenoming. FASEB J . 24, 3479–3489 (2010). www.fasebj.org

The protein purity is generally checked using SDS‐PAGE, where densitometry could be used to quantify the protein bands. In literature, few studies have been reported using image analysis for the quantification of protein in SDS‐PAGE: that is, imaged with Stain‐Free™ technology. This study presents a protocol of image analysis for electrophoresis gels that allows the quantification of unknown proteins using the molecular weight markers as protein standards. Escherichia coli WK6/pHEN6 encoding the bispecific nanobody CH10‐12 engineered by the Pasteur Institute of Tunisia was cultured in a bioreactor and induced with isopropyl β‐D‐1‐thiogalactopyranoside (IPTG) at 28°C for 12 hr. Periplasmic proteins extracted by osmotic shock were purified by immobilized metal affinity chromatography (IMAC). Images of the SDS‐PAGE gels were analyzed using ImageJ, and the lane profiles were obtained in grayscale and uncalibrated optical density. Protein load and peak area were linearly correlated, and optimal image processing was then performed by background subtraction using the rolling ball algorithm with radius size 250 pixels. No brightness and contrast adjustment was applied. The production of the nanobody CH10‐12 was obtained through a fed‐batch strategy and quantified using the band of 50 kDa in the marker as reference for 750 ng of recombinant protein. The molecular weight marker was used as a sole protein standard for protein quantification in SDS‐PAGE gel images.

Effective interventions and treatments for complex diseases have been implemented globally, however, coverage in Africa has been comparatively lower due to lack of capacity, clinical applicability ...

Aging is often associated with a loss of function. We believe aging to be more an adaptation to the various, and often continuous, stressors encountered during life in order to maintain overall functionality of the systems. The maladaptation of a system during aging may increase the susceptibility to diseases. There are basic cellular functions that may influence and/or are influenced by aging. Mitochondrial function is amongst these. Their presence in almost all cell types makes of these valuable targets for interventions to slow down or even reserve signs of aging. In this review, the role of mitochondria and essential physiological regulators of mitochondria and cellular functions, ion channels, will be discussed in the context of human aging. The origins of inflamm-aging, associated with poor clinical outcomes, will be linked to mitochondria and ion channel biology.

Scorpion venom, containing highly toxic, small polypeptides that diffuse rapidly within the patient, causes serious medical problems. Nanobodies, single-domain antigen-binding fragments derived from dromedary heavy-chain antibodies, have a size that closely matches that of scorpion toxins. Therefore these nanobodies might be developed into potent immunotherapeutics to treat scorpion envenoming. Multiple nanobodies of sub-nanomolar affinity to AahII, the most toxic polypeptide within the Androctonus australis hector venom, were isolated from a dromedary immunized with AahII. These nanobodies neutralize the lethal effect of AahII to various extents without clear correlation with the kinetic rate constants k_on or k_off, or the equilibrium dissociation constant, K_D. One particular nanobody, referred to as NbAahII10, which targets a unique epitope on AahII, neutralizes 7 LD₅₀ of this toxin in mice, corresponding to a neutralizing capacity of approx. 37000 LD₅₀ of AahII/mg of nanobody. Such high neutralizing potency has never been reached before by any other monoclonal antibody fragment.